312
FXUS65 KPIH 310838
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
238 AM MDT Fri May 31 2024

.SHORT TERM...Today and Saturday
Quiet weather expected to round out the work week as weak upper
level ridging builds over the region today. This will allow for
mostly clear skies throughout the day, light winds and no
precipitation. The morning will start out chilly, especially outside
of the urban areas where a Frost Advisory continues until 8AM.
Temperatures along the interstate corridors are still generally in
the 40s but outside of those areas upper 30s have been observed.
Under high pressure, temps will rise quickly this morning and
nearing seasonal norms for daytime highs which means upper 60s and
lower 70s in the valley locations, 60s in the mountains. Not
expecting any frost concerns overnight Friday into Saturday as
overnight lows will generally be in the low to mid 40s.

Warming trend continues into the day Saturday with upper 70s and
lower 80s looking likely throughout the Snake Plain and Magic
Valley. A weak shortwave moving well north of the region will likely
bring increasing clouds throughout the day. Could get a few showers
and thunderstorms to develop as well later in the afternoon and into
the evening. Hi-res CAMs are much more aggressive with this
compared to the NBM which is nearly dry regionwide. For now, the
forecast at least shows low-end PoPs along the Montana Divide and
into the eastern highlands but could see a greater expansion on
subsequent forecasts based on model trends. McKaughan

.LONG TERM...Sunday through next Friday.
While we will be in nearly zonal flow on Sunday, a weak shortwave
will pass through our area and keep a 20 to 40 percent chance of
showers and storms around the upper Snake Plain and northern half of
the Eastern Highlands. Sunday will be warm with highs in the 60s and
70s with wind gusts 25 to 35 mph through much of eastern Idaho. Some
discrepancies remain for the track of the low across southern Canada
on Monday with the ECMWF wanting to dig it farther south into north-
central Montana while the GFS keeps it in Canada. While the models
do have their differences, both want to bring in showers and storms
for the day. The best chance for those will be in the Central
Mountains and Eastern Highlands, but even the Snake Plain, Magic
Valley, and Southern Hills will have at least a 30 to 50 percent
chance of precipitation on Monday. The bulk of the moisture will
fall in central Idaho with a 30 to 50 percent chance of QPF of a
half an inch up in the Stanley area and a 10 to 30 percent chance of
the same in the Island Park area throughout Monday into early
Tuesday. This is the "Marginal" risk area the WPC has highlighted in
their Day 4 Excessive Rainfall Outlook. Elsewhere, the 75th
percentile QPF totals generally range from a tenth to two tenths of
an inch. This system will also keep the breezy winds around,
especially in the upper Snake Plain/Mud Lake/Arco Desert areas where
there is already a 40 to 60 percent chance of gusts reaching 45 mph.
A few showers will linger into Tuesday morning and the wind will
continue to gust 25 to 35 mph.

After Tuesday, high pressure moves in and the heat really kicks up.
Highs on Wednesday will be in the 70s and 80s and for Thursday and
Friday many of us will make a run at hitting our first 90s of 2024.
There is a 40 to 60 percent chance that the lower Snake Plain and
eastern Magic Valley will hit 90 by Friday afternoon.
AMM


&&

.AVIATION...
No major aviation concerns today with weak high pressure building
over the region. Winds will be light and skies mostly clear
throughout the period. VFR to prevail. McKaughan


&&

.FIRE WEATHER...
Northwest flow aloft continues today and our weather remains warm
and dry. Highs will again be in the 60s, though parts of the Snake
Plain and Magic Valley will return to the low to mid 70s. Winds will
be light for most with gusts around 20 to 25 mph in the Arco
Desert/Mud Lake area. Expect min RHs to be in the teens and 20s
throughout eastern Idaho today and tomorrow. We warm up for
Saturday, too, with highs almost 10 degrees warmer than today in the
Magic Valley and Snake Plain. A weak shortwave passing through this
weekend brings a 20 to 40 percent chance for some dry thunderstorms
up along the Idaho/Montana state line and in the Eastern Highlands.
A more organized system looks to bring a more widespread mix of wet
and dry storms to eastern Idaho on Monday before we dry out and
really heat up in the second half of next week.
AMM

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 8 AM MDT this morning for IDZ051>054.

&&

$$